The solid oxide fuel cell, hereinafter referred as SOFC, has advantages of high conversion efficiency, low acoustic noise, low environment pollution, high reliability, fuel diversity, and potential of challenging the internal combustion engine especially at a time when the petroleum reserve is getting lower and lower, hydrogen energy is uprising for the future problem of energy shortage; SOFC becomes a key focus for a new energy source.
The main components of solid oxide fuel cell stack class, SOFC-Stack class, that are used in plate type solid oxide fuel cell, SOFC, includes: an electrolyte membrane, a cathode layer, a cathode current collector, an anode layer and an anode current collector, wherein, said electrolyte membrane is set between sides of a cathode layer and anode layer, so that, said electrolyte membrane, said cathode layer, and said anode layer constitute a unit of membrane electrode assembly, MEA, said cathode current collector is set on the other side of said cathode layer, and said anode current collector is set on the other side of said anode layer
Presently, the key objectives of making MEA are high performance, high durability, high stability, and low degradation rate. The key conditions for reaching the above objectives are the materials and structure of MEA. When the materials and structure of MEA are changed, the characteristics of MEA will be changed accordingly.
As to the materials, the most commonly used electrolyte is ytteria-stabilized zirconium oxide, YSZ. Commonly used anode material is NiO-doped ytteria-stabilized zirconium oxide, NiO/YSZ, commonly used cathode material is strontium-doped LaMnO3, LSM, or strontium- and ferrous-doped LaCoO3, LSCF.
The cathode current collector is usually comprised of net or mesh made from Pt or Ni, the cathode current collector is mainly comprised of mesh made from Pt or Ag.
All research institutes in the world are endeavoring in the improving of materials development and technology in material treatment to reduce impedance, increase ionic conductivity, electrical conductivity, power density, and improving the performance efficiency of SOFC.
However, even said components constituted with good materials, still may not be enough to improve the efficiency of SOFC, and have to package the said components into SOFC-Stack class with superb efficiency, so that a plurality of SOFC-Stack class can be effectively connected by a series connection or parallel connection, thereinafter, fabricate a suitable SOFC power generation system, to satisfy the requirement for different voltage or current. Since the level of technology in packaging SOFC-Stack is high, not only tight sealing MEA into SOFC-Stack forming a separated anode chamber and cathode chamber, and tight sealing to become an independent closed system, to perform effective electro-chemical reaction, ensuring an open circuit voltage higher than 1.0V, increasing the MEA life, on the other hand, let the cathode current collector and the anode current collector closely and completely contact the cathode and anode of MEA, effectively conduct the current produced by electro-chemical reaction in MEA to improve electrical power efficiency. With these two basic requirements, on the one hand preventing power consumption caused by bad contact, on the other hand, avoiding damage to MEA components caused by too much contact pressure.
Therefore, a measurement process and measurement apparatus for determination of the optimum contact pressure among components of a solid oxide fuel cell stack in the packaging process is highly desirable, so that, the damage of components in packaging SOFC-Stack class can be reduced and the optimum electrical contact among components can be reached.